Factors underlying human errors in air traffic control

A research project submitted in partial fulfilment of the requirements for the degree of MA by coursework and research report in the field of Industrial/Organisational Psychology in the Faculty of Humanities, University of the Witwatersrand, Johannesburg, 14th February 2014The main objective of Air Traffic Control is to ensure the safe and orderly movement of aircraft through airspace. The primary aim of this study was to explore and identify the factors underlying human error in Air Traffic Control, based on safety event reports from the years 2010 to 2012. A total of 84 incident reports were analysed from airports spanning South Africa. Core factors that were explored included human factors, demographic factors, external factors, shift variables, risk factors and stated causal factors. This was done through the use of content analysis, cluster analyses and logistic regressions. The main results showed that errors in information processing factors, physical workplace designs, poor co-ordination standards and lack of memory cues are predictors of safety events. It was also established that lapses are predictors of poor information processing in controllers whilst poor workplace designs are a predictor of lapses. Finally, a lapse in itself is a predictor of safety events. These finding may direct future research into the possibility of lapses as a mediating variable between poor workplace designs and information processing errors

Toward a Topography of Cross-Cultural Theatre Praxis

In this essay we attempt to map out a conceptual framework for analyzing a cluster of related practices subsumed under the broad banner of "cross-cultural theatre". For the purposes of our discussion, cross-cultural theatre encompasses public performance practices characterized by the conjunction of specific cultural resources at the level of narrative content, performance aesthetics, production processes, and/or reception by an interpretive community. The cultural resources at issue may be material or symbolic, taking the form of particular objects or properties, languages, myths, rituals, embodied techniques, training methods, and visual practices - or what James Brandon calls "cultural fragments" (1990:92). Cross-cultural theatre inevitably entails a process of encounter and negotiation between different cultural sensibilities, although the degree to which this is discernible in any performance event will vary considerably depending on the artistic capital brought to a project as well as the location and working processes involved in its development and execution

Motor evoked potentials in patients with chronic whiplash-associated disorder grade II

Background and purpose It is common belief that psychological problems influence the persistence of complains in patients with so-called mild whiplash-associated disorders (WADs). The usefulness of motor evoked potentials (MEPs) is investigated in patients with grade II WAD and remaining complains for more than 6 months. Patients and methods Twenty consecutive patients, aged between 24 and 58 years, with persistent neck pain for months after a car accident were included. All patients had a magnetic resonance imaging (MRI) of the cervical spine and cord. Central (CMCT) and peripheral motor conduction times (PMCT) were evaluated by registration in the biceps brachii muscle (C5–C6) and in the abductor digiti minimi muscle (C7–C8–Th1). Results Thirteen patients had prolonged CMCT or/and PMCT compared to 7 with normal values. On MRI discus bulging C5–C6, without abnormal signal changes in the cervical spinal cord was observed in 6 of the patients with disturbed MEPs compared to 3 without. Out of 7 patients, who had repeated MEPs after 6 months, 3 of them had an improvement of their conduction time. The patients with prolonged MEP conduction times were older than those with normal values (p=0.007). Conclusions MEP examination has to be performed in all patients with persistent complains even in the absence of objective neurological signs and non-significant changes on imaging

An exploratory study of the relationship between fathering and self-esteem of young adult women

The present study investigated the relationship between variables of father’s behaviour and their daughter’s levels of self-esteem - both were explored based on the perceptions of the daughter. Self-esteem was viewed as the measure of worthiness that one attributed to oneself, whilst the variables of father’s behaviour included support, punishment, control, rejection, indulgence, autonomy and protectiveness. The same elements of mother’s behaviour were also considered to see how they related to their daughter’s self-esteem; the primary motive for doing this was to provide a contrast to the outcome of the fathering information. The participation of seventy-seven young adult women between the ages of 21 and 34, and from different race groups and cultural backgrounds was requested through a number of associates who then passed the relevant questionnaires on to their associates. Respondents were asked to return the questionnaires fully completed, and data on father variables and self-esteem were then used from these questionnaires. Statistical analysis involved non-parametric analyses in the form of Spearman’s Correlation Rank and demonstrated a significant, negative correlation between protectiveness and self-esteem (r =-.368, p<0.001, 13.54% of variance) only for the father behaviours, while for the mother behaviours significant correlations existed between praise and self esteem, rejection and self-esteem, punishment self-esteem and protectiveness and the young adult women’s self-esteem. Theoretically and practically the implications of the findings suggest that parents and the roles they play may have an impact on their daughter’s self-esteem, at least for this sample, and thus future research into the meanings of the above findings and their impact on children - or more specifically - female children is a worthwhile undertaking, as is consideration of the stereotypical gender roles that society upholds.Brenda Radeb

Metal ion-dependent biological properties of a chelator-derivatised somatostatin analogue for tumour targeting

A publicar na Revista Chemistry a European JournalSomatostatin-based radioligands were shown to have sensitive imaging properties for neuroendocrine tumours and their metastases. The potential of [55Co]DOTATOC (DOTATOC = 4,7, 10-tricarboxymethyl-1,4,7,10- tetraazacyclododecane-1-yl-acetyl-DPhe- Lys-Tyr-D-Trp-Lys-Thr-Lys-1- threoninol (disulfide bond) as a new radiopharmaceutical agent for PET was evaluated. 57Co was used as a surrogate of the positron emitter 55Co and the pharmacokinetics of [57Co]DOTATOC was investigated using two nude mouse models. The somatostatin receptor subtype (sst1-5) affinity profile of [natCo]DOTA-TOC was assessed using autoradiographic methods on membranes transfected with human somatostatin receptor subtypes. These studies revealed that [57Co]DOTATOC is an sst2-specific radiopeptide presenting the highest affinity ever found for the sst2 receptor subtype. The rate of internalisation into the AR4-2J cell line also was the highest found for any somatostatin-based radiopeptide. Biodistribution studies, performed in nude mice bearing the AR4-2J tumour or a transfected HEK-sst2 cell-based tumour, showed high and specific uptake in the tumour and in other sst receptor-expressing tissues reflecting the high receptor binding affinity and the high rate of internalisation. The pharmacologic differences between [57Co]DOTATOC and [67Ga]DOTATOC were discussed in terms of the structural parameters found for the chelate models CoII(DOTA)2- and GaIII(DOTA)-, whose X-ray structures were determined. Both chelates show sixfold coordination in pseudooctahedral arrangements

The referendum in South Africa: A triumph of the spirit?

I can sing a hymn to the glory of my land, from the ashes something stirs, new voices are being heard. I can look with love at the harsh landscape pockmarked by ghettoes, in the dust and the dirt new voices sing new songs. (Achmat Dangor

Cerebral microinfarcts: the invisible lesions

The association between small but still visible lacunar infarcts and cognitive decline has been established by multiple population-based radiological and pathological studies. Microscopic examination of brain sections reveals even smaller but substantially more numerous microinfarcts, the focus of the current review. These lesions often result from small vessel pathologies such as arteriolosclerosis or cerebral amyloid angiopathy. They typically go undetected in clinical-radiological correlation studies that rely on conventional structural MRI, though the largest acute microinfarcts may be detectable by diffusion-weighted imaging. Given their high numbers and widespread distribution, microinfarcts may directly disrupt important cognitive networks and thus account for some of the neurologic dysfunction seen in association with lesions visible on conventional MRI such as lacunar infarcts and white matter hyperintensities. Standardized neuropathological assessment criteria and development of non-invasive means of detection during life would be major steps towards understanding the causes and consequences of the otherwise macroscopically invisible microinfarct

A Sociotechnical Perspective on Software-defined Networking Adoption in Large-Scale ISPs

This study investigates the sociotechnical factors shaping Software‐Defined Networking (SDN) adoption within a major African Internet Service Provider (ISP). Employing a qualitative, single case-study, we conducted semi‐structured interviews with network professionals across provisioning, support, automation, and core teams. Using a thematic analysis, we identified key technical challenges: vendor inconsistency, software maturity and reliability, lack of trust and stability, and cost‐benefit consideration, while technical enablers include efficiency gained through automation, cost-benefit analysis and transformative potential. Social dimensions highlight knowledge gaps, skill erosion, developing a new way of thinking, resistance to change, and the need for a learning culture, while social enablers encompass factors such as perceived cost‐effectiveness, strong vendor relationships, and evolving network professional roles. These findings are synthesized into a conceptual framework illustrating the dynamic interplay of technical and social dimensions. Grounded in the lived experiences of network professionals, this paper offers actionable insights for ISPs navigating SDN transitions.This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.fi=vertaisarvioitu|en=peerReviewed

A team decision framework for quality decision outcomes

This paper outlines the Team Decision Framework which follows on from our previous work on optimising the quality of decision-making in groups. The TDF is proposed as a model of the skills and abilities which we have termed ?intelligences? that should ideally be present in order for groups making decisions to achieve their full potential. The paper describes the intelligences and outlines the development of the measuring instrument, using Structural Equation Modelling and exploratory factor analysis. The TDF is designed to profile groups? decision-making capabilities. It is anticipated that such profiling might be used for diagnostic, training and comparative research purposes

A Novel Model of Mixed Vascular Dementia Incorporating Hypertension in a Rat Model of Alzheimer's Disease.

Alzheimer's disease (AD) and mixed dementia (MxD) comprise the majority of dementia cases in the growing global aging population. MxD describes the coexistence of AD pathology with vascular pathology, including cerebral small vessel disease (SVD). Cardiovascular disease increases risk for AD and MxD, but mechanistic synergisms between the coexisting pathologies affecting dementia risk, progression and the ultimate clinical manifestations remain elusive. To explore the additive or synergistic interactions between AD and chronic hypertension, we developed a rat model of MxD, produced by breeding APPswe/PS1ΔE9 transgenes into the stroke-prone spontaneously hypertensive rat (SHRSP) background, resulting in the SHRSP/FAD model and three control groups (FAD, SHRSP and non-hypertensive WKY rats, n = 8-11, both sexes, 16-18 months of age). After behavioral testing, rats were euthanized, and tissue assessed for vascular, neuroinflammatory and AD pathology. Hypertension was preserved in the SHRSP/FAD cross. Results showed that SHRSP increased FAD-dependent neuroinflammation (microglia and astrocytes) and tau pathology, but plaque pathology changes were subtle, including fewer plaques with compact cores and slightly reduced plaque burden. Evidence for vascular pathology included a change in the distribution of astrocytic end-foot protein aquaporin-4, normally distributed in microvessels, but in SHRSP/FAD rats largely dissociated from vessels, appearing disorganized or redistributed into neuropil. Other evidence of SVD-like pathology included increased collagen IV staining in cerebral vessels and PECAM1 levels. We identified a plasma biomarker in SHRSP/FAD rats that was the only group to show increased Aqp-4 in plasma exosomes. Evidence of neuron damage in SHRSP/FAD rats included increased caspase-cleaved actin, loss of myelin and reduced calbindin staining in neurons. Further, there were mitochondrial deficits specific to SHRSP/FAD, notably the loss of complex II, accompanying FAD-dependent loss of mitochondrial complex I. Cognitive deficits exhibited by FAD rats were not exacerbated by the introduction of the SHRSP phenotype, nor was the hyperactivity phenotype associated with SHRSP altered by the FAD transgene. This novel rat model of MxD, encompassing an amyloidogenic transgene with a hypertensive phenotype, exhibits several features associated with human vascular or "mixed" dementia and may be a useful tool in delineating the pathophysiology of MxD and development of therapeutics